1. Field of the Invention
The present invention relates to a joint connector and a method of manufacturing metal fittings for connection with the joint connector.
2. Description of the Related Art
A connector assembly is disclosed in Japanese Unexamined Patent Publication (kokai) No. 8-64314. In this publication, as shown in FIG. 1, a connector element is provided by firstly stacking two lead frames 2, 3 each having a plurality of contacts 1 on each other, welding the lead frames 2, 3 together, subsequently fixing them with an insulating housing block 4, and finally eliminating all of band-shaped carriers of the lead frames 2, 3. Next, as shown in FIG. 2, the contacts 1 of the completing connector element are inserted into contact-accommodating spaces formed in another insulating housing block 5.
In the above-mentioned conventional connector assembly, however, it has been necessary to prepare the insulating housing blocks 4 of various kinds corresponding to the number of layers defined in the insulating housing block 5 because the blocks 4, 5 are different from each other in structure, thereby causing the number of components to be increased. Therefore, the production/management of the components and the assembling work become troublesome to make it difficult to reduce the manufacturing cost.
Further, since the contacts 1 of each connector element are to be bent after the lead frames 23 have been stacked on each other, there is a problem and the welding part may be subjected to stress.
Additionally, in the conventional connector assembly, it has been impossible to perform the connection between the connector elements in the vertical direction, thereby requiring connection wires.
Under such a circumstance, it is therefore an object of the present invention to provide a joint connector of low cost, which is capable of facilitated assembling work and various circuit arrangements and which also allows a reliable connection to be effected with ease.
The object of the present invention described above can be accomplished by a joint connector comprising:
a metal fittings assembly including two terminals in stack, each terminal having a band-shaped carrier and a plurality of terminal units connected to the carrier at substantial right angles and arranged in parallel with each other in the longitudinal direction of the carrier; and
a housing having a plurality of unit accommodating parts formed for accommodating the terminal units of the terminals therein;
wherein the two terminals are laid to overlap each other while the terminals are shifted from each other in a predetermined length in the longitudinal direction of the carriers, and the so-overlapped carriers are welded to each other; and
wherein either one of the upper and lower terminals in stack is provided, at respective joint portions between the carrier and the terminal units, with bending parts which result by bending the joint portions by a plate thickness of the carrier of the other terminal, thereby positioning the adjoining terminal units of the terminals in an identical plane.
In the present invention, since two terminals are overlapped on each other while one of the terminals is shifted from the other terminal in the predetermined length in the longitudinal direction of the carriers, it is possible to reduce a space between the adjoining terminal units. Thus, the metal fittings assembly can be small-sized thereby to also miniaturize the housing for accommodating the metal fittings assembly. Additionally, owing to the provision of the bending parts, the terminal units of the metal fittings assembly are positioned in the identical plane. Consequently, it is possible to provide the housing with the unit accommodating parts (e.g. grooves) in the same level, thereby simplifying the structure of a mold for the housing.
According to the second aspect of the invention, in the above-mentioned invention, the terminals are laid to overlap each other while the terminals are also shifted from each other in a direction perpendicular to the longitudinal direction of the carriers.
In this case, with the above arrangement, it is possible to dispose the terminal units in the identical plane by bending the terminal being shifted forward.
According to the third aspect of the invention, in the above-mentioned invention, the two terminals constituting the metal fittings assembly are both identical in configuration, while each of the band-shaped carriers of the terminals is obtained by cutting a continuous long carrier piece by a predetermined length.
In this case, since the terminals are both identical in configuration, there is no need to increase the sorts of components. Further, even when the terminals are overlapped while being shifted from each other back and forth, the simple bending of the terminal allows respective front ends of the terminal units to be positioned uniformly.
According to the fourth aspect of the invention, in the above-mentioned invention, each of the terminals has a plurality of positioning holes formed in the carrier at predetermined intervals in the longitudinal direction of the carrier, the positioning holes formed in one of the terminals being profiled so as to agree with the positioning holes formed in the other terminal when the terminals are laid to overlap each other.
In this case, if only according the positioning holes of the terminal with those of the other terminal, then the mutual positioning of the terminals can be accomplished with ease.
According to the fifth aspect of the invention, in the above-mentioned invention, each of the terminal units has a connecting piece formed on a leading end portion of the terminal unit so as to project upward and an inserting piece formed on the leading end portion so as to extend downward, the connecting piece being engageable with the inserting piece of the other terminal unit.
According to the sixth aspect of the invention, in the above-mentioned invention, the housing is provided, in each of the unit accommodating parts, with a slit into which the inserting piece of the terminal unit is to be inserted.
Owing to the provision of the connecting piece, the inserting piece and the slit, under condition that a plurality of housings are stacked vertically, it is possible to electrically connect the upper and lower terminal units with each other through the slit.
According to the seventh aspect of the invention, in the above-mentioned invention of the sixth aspect, the housing is provided with an engagement projection and a locking piece, the engagement projection being engageable with the locking piece when another housing identical to the housing is prepared and both of the housings are laid to overlap each other. In this case, owing to the provision of the engagement projection and the locking piece, it is possible to stack a plurality of housings while the engagement projection of one housing is engaged with the locking piece of the other housing.
According to the invention, there is also provided a method of manufacturing a metal fittings assembly for a joint connector, comprising:
preparing a pair of terminals each having a band-shaped carrier and a plurality of terminal units connected to the carrier at substantial right angles and arranged in parallel with each other in the longitudinal direction of the carrier;
overlapping the terminals each other;
bending respective joint portions between the carrier of one of the terminals and the terminal units of the one terminal by a plate thickness of the carrier of the other terminal, thereby positioning the adjoining terminal units of the terminals in an identical plane;
welding the band-shaped carriers of the terminals on each other; and
cutting the carriers of the terminals for every predetermined number of terminal units required in accordance with the constitution of a connecting circuit as a product.
In this invention, by bending the joint portions of one terminal, it is possible to position the adjoining terminal units of the pair of terminals in the identical plane. Additionally, under condition that a plurality of housings are stacked vertically, it is possible to electrically connect the upper and lower terminal units with each other.